Based on homology cloning techniques, we isolated the polyphenol oxidase gene (3 transcripts：DlPPO1a，DlPPO1b, and DlPPO1c; Genbank：KM387405, KM516087, and KM516088) from leaves of longan (‘Sijimi’ cultivar) by RTPCR and RACE．The fulllength cDNA sequence of DlPPO1a，DlPPO1b, and DlPPO1c were 1 969 bp, 1 960 bp and 1 920 bp, respectively, containing a 1 800 bp open reading frame (ORF) which encoded 599 amino acids; DlPPO1 shared high homology with PPO gene of Litchi chinensis, Canarium album, and Populus euphratica, etc. Bioinformatic analysis revealed that the deduced DlPPO1 protein with conserved domains shared the typical characteristics of the PPO family. QPCR analysis indicated that during somatic embryogenesis (SE) in longan, the expression level of DlPPO1 rose from the stage of heart embryo and then reached the highest at the stage of the cotyledon embryo, which suggested that DlPPO1 might play important roles during the middle and late stages of longan SE. It was detected that DlPPO1 abundantly accumulated in longan leaves, followed by flower buds; there was lower expression in other longan tissues. After exposure to phytohormones and abiotic stress, the expression of DlPPO1 was induced by salicylic acid (SA), methyl jasmonte (MeJA), NaCl, mannitol, and PEG treatments. Consequently, it suggested that DlPPO1 might participate in abiotic stress responsiveness.